Nearly half of doctors and physical therapists surveyed were willing to return a child to sport after a knee injury despite more than minimal pain, continued swelling, and limited range of motion in the joint, finds a surprising new Canadian study.

While previous studies reported that older athletes in elite sports were often returned to activity despite continued pain, whether such a practice is appropriate for younger athletes remains to be seen.

The study is in the October 2011 issue of the British Journal of Sports
Medicine.1

Key findings

Doctors, PTs and ATs in the survey generally agreed that the absence of knee pain and swelling, and the regaining of full
range of motion in joint, muscle strength, sport-specific skills and
balance, should all be weighed, but disagreed on the weight each should be given, and how much impairment was acceptable before a child would be allowed to return to sports.

Pain:

Overall, doctors and physical therapists considered pain the most important factor in deciding return to play, with impact of pain on knee function the most frequent pain measurement considered.

While sports medicine guidelines for children and adolescents recommend against athletes returning to play with more than a "minimal" level of pain, nearly half (45%) of those surveyed were willing to return a child to activity with a higher pain level. While older athletes in elite sports often return to activity in such pain, the level appropriate for children has not been determined and requires more research, the study said.

Range of motion(ROM):

A majority of doctors and physical therapists required full ROM to return to activity, consistent with previous surveys.

But, as with pain, ROM was chosen as the first or second most important factor in the return to play decision by less than half of those surveyed, suggesting that many would likely allow a child to return to sports despite limited range of motion in the knee.

Muscle strength:

Most experts recommend a minimal muscle strength of 90% compared to the uninjured side.

A majority of the doctors and physical therapists surveyed believed that 90% was not enough, and favored a completely normal muscle strength before returning a child to activity.

Swelling

The preferred method for measuring swelling in the knee was palpatation. Whether palpatation would also be the preferred measure if the injury was to a different joint (eg, ankle, elbow) or other area of the body (eg. calf), requires further study.

While some guidelines specify that, when swelling is persistent and recurrent, the acceptable level should be closer to normal, a majority of physical therapists were willing to return athletes to play with mild swelling.

Most doctors, however, were more cautious, returning a child to sports only when swelling was not present.

Balance

Doctors and physical therapists alike perferred a simple one-leg, eyes-closed test of balance, preferring the test over the timed dynamic one-leg eyes-closed test found to be more reliable in earlier studies, at least for adolescents, because it required a special foam pad not available in all examining rooms.

No child-specific guideline exists for balance and proprioception (sense of relative position of body parts to one another), and the only published guideline requires "good" balance.

Although approximately half of doctors and PTs required normal balance before allowing a child to return to sports, it was the least important factor in the return to play decision, suggesting that most children are likely allowed to retunrn despite less than normal balance, which is difficult to determine, in any event, in the absence of preseason testing and in growing teens.

"The marked difference for
MDs may reflect a different philosophy, training or focus on health
issues, [which] needs to be explored in future studies if
interdisciplinary guidelines for return to sport for children are to be
developed," said lead author, Mathieu Boudier-Revéret of the School of
Physical and Occupational Therapy at McGill University in Montreal,
Quebec, Canada.

Gray areas

The challenge for doctors and physical therapists, says Keith Cronin, a physical therapist in St. Louis, is in explaining to parents the many gray areas in the return to play decision, including the following factors:

the sport the athlete is playing

the athlete's genetic make-up

the athlete's committment to continued rehabiliation at home

range of motion in the joint

swelling

joint stability/mobility

injury history

balance

flexibility

integrity of the damaged tissue; and

the surface the athlete plays on.

For example, Cronin says, he would allow a right-handed pitcher with a right ACL tear to return faster than a right-handed pitcher with a left ACL tear because the left leg is his landing leg, which the pitching follow-through subjects to more pressure and uncontrolled rotation.

Another example: Cronin would allow a football player with mild pain while running, but not while walking, climbing stairs, or sleeping, to return to practice, but that same football player with no "reported" pain while running not to return to play if he was limping around the house and experienced pain while sleeping.